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<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>数学运算</title>
	<script type="text/javascript">
		
		var a = 30;

		var b = 7;

		var c = a%b;

		var d = 0;

		var e = d%b;


		alert(c);  // 弹出2

		alert(e);  // 弹出0;

		var f

		f = f + 2;  // 等同于 f+=2；








	</script>
</head>
<body>
	
</body>
</html>